In the past, there has been proposed, as a thin light emitting device excellent in heat radiation performance, an LED package including a submount substrate, an LED element mounted on the submount substrate, a spacer having a cavity, and an optical element (Document 1 [JP 2006-270046 A]), for example.
The optical element is formed of, for example, a glass plate.
In the LED package, the LED element is bonded to patterned electrodes, via solder bumps formed on electrodes of the LED element, by flip-chip bonding.
The spacer is formed of a silicon substrate, for example, and is bonded to the submount substrate with an adhesive sheet. The optical element is formed of, for example, a glass plate, and is bonded to an upper surface of the spacer with an adhesive sheet.
Further, there has been known a method for manufacturing a light emitting device, including mounting an LED element on an inorganic material substrate by flip-chip bonding, and subsequently performing a step of covering with a wavelength conversion layer, and thereafter performing a step of bonding the inorganic material substrate to a glass cover (Document 2 [JP 2011-40577 A]).
The inorganic material substrate is provided with AuSn electrodes for mounting the LED element by flip-chip bonding, and an Au layer serving as an adhesion foundation layer for bonding the glass cover.
In the fields of light emitting devices, there would be a demand to improve reliability and reduce production cost.